package com.tanhua.backstage.service;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.time.Duration;
import java.util.Random;

@Service
@Slf4j
public class CheckService {

    @Autowired
    RedisTemplate<String, String> redisTemplate;
    public static final String VALIDATE = "VALIDATE_CODE_";

    /**
     * 获取对应UUID的缓存验证码值
     *
     * @param uuid
     * @return
     */
    private String getValidate(String uuid) {
        return VALIDATE + uuid;
    }

    /**
     * 业务层实现功能:获取验证码图片
     *
     * @param uuid
     * @return
     */
    public BufferedImage getImage(String uuid) {

        int width = 120;
        int height = 50;

        //1.创建一对象，在内存中图片(验证码图片对象)
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);


        //2.美化图片
        //2.1 填充背景色
        Graphics g = image.getGraphics();//画笔对象
        g.setColor(Color.black);//设置画笔颜色
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("黑体", Font.BOLD, 30));

        //2.2画边框
        g.setColor(Color.yellow);
        g.drawRect(0, 0, width - 1, height - 1);

        String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz0123456789";
        //生成随机角标
        Random ran = new Random();
        StringBuilder strb = new StringBuilder();
        for (int i = 1; i <= 4; i++) {
            int index = ran.nextInt(str.length());
            //获取字符
            char ch = str.charAt(index);//随机字符
            strb.append(ch);
            //2.3写验证码
            g.drawString(ch + "", width / 5 * i, height / 2);
        }
        String code = strb.toString();
        redisTemplate.opsForValue().set(getValidate(uuid), code, Duration.ofMinutes(2));

        //2.4画干扰线
        g.setColor(Color.red);

        //随机生成坐标点

        for (int i = 0; i < 4; i++) {
            int x1 = ran.nextInt(width);
            int x2 = ran.nextInt(width);

            int y1 = ran.nextInt(height);
            int y2 = ran.nextInt(height);
            g.drawLine(x1, y1, x2, y2);
        }
        ImageIO.setUseCache(false);
        return image;
    }
}
